June 1999

We have developed a new numbering system for the CG series rootstocks in response to feedback I have received from our cooperators. These numbers will supercede the ones used in the past, and it will require careful effort to maintain a consistent nomenclature in discussion, presentation, and the literature.

This system will have two stages: a Testing Number and a Name. Genotypes do not receive a Name until they have been thoroughly tested, patented, and are ready for commercial sale. A separate testing number and name is the conventional method for releasing new germplasm in all crop species.

The testing numbers will be designated as CGXXXX where XXXX is a 4 digit number. The first digit corresponds to the approximate size class of the genotype (a 1 to 10 scale where 1 is M.27 sized and 10 is standard seedling, M.9 EMLA would be a 3) and the rest of the number is an identifier (usually a progeny number). The approximate size class is determined during initial orchard trials here in Geneva, prior to any distribution elsewhere. Thus the new testing numbers include valuable information to our cooperators.

When the genotype is released commercially we will refer to the rootstock with a name, in the format G.#X, where the # is a number (1-9) corresponding the size class determined during intermediate stage testing, and X is a consecutive letter (A to Z) corresponding to the time of release of the genotype. For example, the hypothetical release G.2C is reserved for the third rootstock we release in the size class that is intermediate to M.27 and M.9.

We will not re-name the genotypes that are already commercially available (G.16, G.30, G.65).

I apologize for the confusion that this new numbering system is going to generate, but I assure you that it will decrease the level of confusion that would result in the near future by not changing the system. One of the reasons that there have been problems with misidentifications using the earlier CG numbering system may be that these are sequentially assigned numbers for a given cross in a given year. The problem arises when we identify more than one elite rootstock genotype with a given progeny number. For example, our next release from the program is G.5A, formerly known as G.11 and CG.11. We have three additional elite genotypes in advanced trials with the progeny number 11, all from different crosses, years, and all with very different horticultural properties. Under the current system these could all be called CG.11, seriously confusing our efforts to provide accurate information. Our new system will prevent this type of duplication in the future.

For all of our grower and nursery cooperators, I strongly recommend that you update your records to include the new testing numbers. To help you with this, I am including a correspondence table that shows the release name, new CG testing number, old CG testing number, the year the cross was made, pedigree, and current stage in the breeding program (current in summer 1999). Click for an explanation of breeding program stages. If you have questions, or if you would like a personalized correspondence table for genotypes you have seen in particular trials, please contact me and I'll be happy to provide one.

This table includes the genotypes that are presently in tests with growers, nurseries, and researchers. The genotypes that are in tests outside Geneva but are not included in this table represent discards from the program. Use this table to update your records, and do not hesitate to contact me to clear up anything that is not perfectly clear. Genotypes are ordered sequentially by the old CG numbering system to aid you in locating the correct testing number.

 

Name	Testing Number	Old Number	Year	Pedig- ree	Stage
G.16	N/A	CG.16	81	O3R5	10
G.30	N/A	CG.30	74	R5M9	10
G.65	N/A	CG.65	74	27BY	10
G.5A	N/A	CG.11	78	26R5	10
	3001	CG.001	84	P2R5	4
	4003	CG.003	76	2XR5	6
	3007	CG.007	75	O3R5	6
	5008	CG.008	80	3OM9	4
	5012	CG.011(CG.75-11)	75	O3R5	6
	4011	CG.011(CG.74-11)	74	O3R5	5
	4013	CG.013	75	O363	6
	3029	CG.029	72	DLM9	6
	4038	CG.038	72	DLM9	4
	3041	CG.041	75	27R5	7
	5046	CG.046	78	6346	6
	5087	CG.087	75	O3R5	6
	4088	CG.088	75	27R5	5
	6143	CG.143	75	27R5	6
	5156	CG.156	74	R5M9	6
	5179	CG.179	76	O3R5	7
	8189	CG.189	75	O3R5	4
	5202	CG.202	75	27R5	5
	5206	CG.206	75	O3R5	6
	4210	CG.210(6210, 76-210)	76	O3R5	5
	6210	CG.210	75	O3R5	7
	4213	CG.213	76	O3R5	6
	4214	CG.214	75	O3R5	6
	8228	CG.228	74	R5M9	6
	6239	CG.239	75	M9R5	4
	4247	CG.247	75	O3R5	6
	6253	CG.253	75	O3R5	6
	5701	CG.701	74	R5M9	6
	7707	CG.707	75	R5M9	7
	6723	CG.723	74	O5M9	6
	6737	CG.737	74	R5M9	5
	5757	CG.757	76	O3R5	6
	7760	CG.760	74	R5M9	6
	9778	CG.778	74	R5M9	6
	4809	CG.809	74	R5M9	6
	4814	CG.814	76	O3R5	6
	6874	CG.874	76	O3R5	6
	6879	CG.879	74	R5M9	6
	3902	CG.902	76	O3R5	4
	5935	CG.935	76	O3R5	7

 

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